Adsorptive removal of selected pharmaceuticals by mesoporous silica SBA-15

• Published in: Journal of hazardous materials Vol. 168; no. 2; pp. 602 - 608
• Main Authors: Bui, Tung Xuan, Choi, Heechul
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.09.2009; Elsevier
• Subjects: Adsorption; Applied sciences; Chemical engineering; Continental surface waters; Exact sciences and technology; General purification processes; Hydrogen-Ion Concentration; Kinetics; Mesoporous silica SBA-15; Natural water pollution; Pharmaceutical Preparations - isolation & purification; Pharmaceuticals; Pollution; Removal; Silicon Dioxide - chemistry; Surface water; Wastewaters; Water treatment and pollution; X-Ray Diffraction; Removal; Mesoporous silica SBA-15; Adsorption; Surface water; Pharmaceuticals; Drug; Second order; Adsorption isotherm; Desorption; X ray diffraction; Modeling; Waste water; Design; Sorption; Transmission electron microscopy; Batchwise; pH; Kinetics; Hydrophilic compound; Organic compounds
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2009.02.072

The removal of five selected pharmaceuticals, viz., carbamazepine, clofibric acid, diclofenac, ibuprofen, and ketoprofen was examined by batch sorption experiments onto a synthesized mesoporous silica SBA-15. SBA-15 was synthesized and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N 2 adsorption–desorption measurement, and point of zero charge (PZC) measurement. Pharmaceutical adsorption kinetics was rapid and occurred on a scale of minutes, following a pseudo-second-order rate expression. Adsorption isotherms were best fitted by the Freundlich isotherm model. High removal rates of individual pharmaceuticals were achieved in acidic media (pH 3–5) and reached 85.2% for carbamazepine, 88.3% for diclofenac, 93.0% for ibuprofen, 94.3% for ketoprofen, and 49.0% for clofibric acid at pH 3 but decreased with increase in pH. SBA-15 also showed high efficiency for removal of a mixture of 5 pharmaceuticals. Except for clofibric acid (35.6%), the removal of pharmaceuticals in the mixture ranged from 75.2 to 89.3%. Based on adsorption and desorption results, the mechanism of the selected pharmaceuticals was found to be a hydrophilic interaction, providing valuable information for further studies to design materials for the purpose. The results of this study suggest that mesoporous-silica-based materials are promising adsorbents for removing pharmaceuticals from not only surface water but also wastewater of pharmaceutical industrial manufactures.